Segment Information - Financial Information Relating to Company's Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 25, 2023	Mar. 26, 2022	Mar. 25, 2023	Mar. 26, 2022	Sep. 24, 2022
Net sales:
Net sales	$ 909,004	$ 954,370	$ 1,536,667	$ 1,615,768
Operating income (loss)
Total operating income	78,041	106,845	78,447	133,059
Interest expense - net	(14,690)	(14,702)	(28,466)	(29,110)
Other income (expense)	595	(369)	2,294	(578)
Income tax expense	15,268	21,488	12,446	23,889
Income including noncontrolling interest	48,678	70,286	39,829	79,482
Net income attributable to noncontrolling interest	563	573	147	760
Net income attributable to Central Garden & Pet Company	48,115	69,713	39,682	78,722
Depreciation and amortization:
Depreciation and amortization	22,109	18,247	43,801	38,449
Assets:
Total assets	3,350,798	3,349,258	3,350,798	3,349,258	$ 3,282,002
Goodwill (included in corporate assets above):
Total goodwill	546,436	511,973	546,436	511,973	546,436
Pet Segment
Net sales:
Net sales	475,203	497,640	891,023	933,642
Garden Segment
Net sales:
Net sales	433,801	456,730	645,644	682,126
Operating segments | Pet Segment
Operating income (loss)
Total operating income	55,255	60,645	94,810	105,896
Depreciation and amortization:
Depreciation and amortization	10,474	9,539	20,586	19,088
Assets:
Total assets	1,058,549	1,101,814	1,058,549	1,101,814	1,069,167
Goodwill (included in corporate assets above):
Total goodwill	277,067	277,067	277,067	277,067	277,067
Operating segments | Garden Segment
Operating income (loss)
Total operating income	49,619	70,511	38,799	76,568
Depreciation and amortization:
Depreciation and amortization	10,818	7,719	21,660	17,339
Assets:
Total assets	1,620,907	1,634,158	1,620,907	1,634,158	1,405,802
Goodwill (included in corporate assets above):
Total goodwill	269,369	234,906	269,369	234,906	269,369
Corporate
Operating income (loss)
Total operating income	(26,833)	(24,311)	(55,162)	(49,405)
Depreciation and amortization:
Depreciation and amortization	817	989	1,555	2,022
Assets:
Total assets	$ 671,342	$ 613,286	$ 671,342	$ 613,286	$ 807,033